public void WillShowViewController(UINavigationController navigationController, UIViewController viewController, bool animated)
 {
     if (viewController is avTouchViewController && _editPropertiesCtrl != null)
     {
         Console.WriteLine (_editPropertiesCtrl.Properties);
         controller.LoadProperties (_editPropertiesCtrl.Properties);
         _editPropertiesCtrl = null;
     }
 }
 void editButtonClicked(object sender, EventArgs e)
 {
     _editPropertiesCtrl = new EditPropertiesController (_appProperties);
     this.NavigationController.PushViewController (_editPropertiesCtrl, true);
 }